Nacy C A, Osterman J V
Infect Immun. 1979 Nov;26(2):744-50. doi: 10.1128/iai.26.2.744-750.1979.
Resident peritoneal macrophage from BALB/c mice were infected in vitro with Rickettsia tsutsugamushi strain Gilliam, and rickettsial growth was estimated by microscopic examination of Giemsa-stained cells. Both number of infected macrophage per culture and number of intracellular rickettsiae per cell increased with time during culture. Treatment of rickettsiae with immune serum before infection macrophage cultures reduced the number of infected macrophage by 50%. Macrophage treated in vitro with lymphokines were able to suppress rickettsial growth in the absence of detectable antibody and exhibited a 75% reduction in infection compared with normal macrophage. We also obtained activated macrophage from immune mice and found that they were refractory to in vitro rickettsial infection. Macrophage populations activated in vitro or in vivo contained a small percentage of cells which supported unrestrained growth of rickettsiae. These data suggest that an early immunological event in experimental scrub typhus infection may be the development of activated macrophage capable of suppressing rickettsial proliferation before the appearance of circulating antibody.
将来自BALB/c小鼠的腹腔巨噬细胞在体外感染恙虫病立克次体Gilliam株，通过对吉姆萨染色细胞进行显微镜检查来评估立克次体的生长。在培养过程中，每个培养物中被感染巨噬细胞的数量和每个细胞内立克次体的数量均随时间增加。在感染巨噬细胞培养物之前用免疫血清处理立克次体，可使被感染巨噬细胞的数量减少50%。在体外用淋巴因子处理的巨噬细胞在没有可检测到的抗体的情况下能够抑制立克次体的生长，与正常巨噬细胞相比，感染减少了75%。我们还从免疫小鼠中获得了活化巨噬细胞，发现它们对体外立克次体感染具有抗性。在体外或体内活化的巨噬细胞群体中含有一小部分支持立克次体不受限制生长的细胞。这些数据表明，在实验性恙虫病感染中，早期免疫事件可能是在循环抗体出现之前能够抑制立克次体增殖的活化巨噬细胞的发育。
